mpich

/* *  mpich7.c *  $Id$ * *  Copyright (C) 2007 Andrew Smirnoff * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * *   */#include <stdio.h>#include <stdlib.h>#include <time.h>#include <unistd.h>#include <string.h>#include "mpi.h"int main(int argc, char* argv[]){     int myrank;     int **a, **b;     int *veca, *vecb;     int *buf;     int i,j,k;     int n;     int next;     int prev;     int min = 2147483647;     int res;          MPI_Status status;          MPI_Init(&argc,&argv);     MPI_Comm_rank(MPI_COMM_WORLD,&myrank);     MPI_Comm_size(MPI_COMM_WORLD,&n);     veca = (int *) malloc(sizeof(int) * n);     buf = (int *) malloc(sizeof(int) * n);     vecb = (int *) malloc(sizeof(int) * n);          if (myrank == 0)     {	  a = (int **) malloc(sizeof(int *) * n);	  b = (int **) malloc(sizeof(int *) * n);	  srand(time(0));	  	  for (i = 0; i < n; i++)	  {	       a[i] = (int *) malloc(sizeof(int) * n);	       b[i] = (int *) malloc(sizeof(int) * n);	       for (j = 0; j < n; j++)	       {		    a[i][j] = rand() % 10;		    b[i][j] = rand() % 10;	       }	  }	  	  printf("a = \n");	  for (i = 0; i < n; i++)	  {	       for (j = 0; j < n; j++)		    printf("%2d ", a[i][j]);	       printf("\n");	  }	  printf("b = \n");	  for (i = 0; i < n; i++)	  {	       for (j = 0; j < n; j++)		    printf("%2d ", b[i][j]);	       printf("\n");	  }	  printf("Sending to processes...\n");	  fflush(stdout);	  for (i = 1; i < n; i++)	  {	       for (j = 0; j < n; j++)	       {		    veca[j] = a[i][j];		    vecb[j] = b[j][i];	       }	       MPI_Send(veca, n, MPI_INT, i, 0, MPI_COMM_WORLD);	       MPI_Send(vecb, n, MPI_INT, i, 0, MPI_COMM_WORLD);	  }	  printf("Sended!\n");	  fflush(stdout);	  for (j = 0; j < n; j++)	  {	       veca[j] = a[0][j];	       vecb[j] = b[j][0];	  }     }     else     {	  MPI_Recv(veca, 2 * n, MPI_INT, 0, 0, MPI_COMM_WORLD, &status);	  MPI_Recv(vecb, 2 * n, MPI_INT, 0, 0, MPI_COMM_WORLD, &status);     }     next = myrank + 1;     prev = myrank - 1;     if (myrank == 0) prev = n - 1;     if (myrank == n-1) next = 0;     for (i = 0; i < n; i++)     {	  res = 0;	  for (j = 0; j < n; j++)	       res += veca[j] * vecb[j] * j;	  	  if (res < min)	       min = res;	  if (i < n)	  {	       MPI_Sendrecv (vecb, n, MPI_INT, next, 0, buf, n, MPI_INT, prev, 0, MPI_COMM_WORLD, &status);	       for (j = 0; j < n; j++)	            vecb[j] = buf[j];	  }     }     if (myrank != 0)	  MPI_Send(&min, 1, MPI_INT, 0, 0, MPI_COMM_WORLD);     else     {	  veca[0] = min;	  for (i = 1; i < n; i++)	       MPI_Recv(&(veca[i]), 1, MPI_INT, i, 0, MPI_COMM_WORLD, &status);	  printf("Result:  ");	  for (i = 0; i < n; i++)	       printf("%d ", veca[i]);	  printf("\n");     }     MPI_Finalize();          free(veca);     free(buf);}